Synthesis and characterization of different complexes derived from Schiff base and evaluation as a potential anticancer, antimicrobial, and insecticide agent

The condensation of (1H-benzimidazole-2-yl) methanamine, with 2-hydroxy naphthaldehyde lead to Schiff base ligand (H2L) (1). This was later reacted with metal salts (ZnCl2, CrCl3·6H2O, and MnCl2·4H2O) to afford the corresponding metal complexes. Biological activity findings indicate that the metal complexes have promising activity against Escherichia coli and Bacillus subtilis and modest activity against Aspergillus niger. The in vitro anticancer activities of Zn (II), Cr (III), and Mn (II) complexes were investigated and the best results were observed with Mn (II) complex as the most potent cytotoxic agent toward human cell lines colorectal adenocarcinoma HCT 116, hepatocellular carcinoma HepG2 and breast adenocarcinoma MCF-7 with 0.7, 1.1 and 6.7 μg of inhibitory concentration IC50 values respectively. Consequently, the Mn (II) complex and ligand were docked inside the energetic site of ERK2 and exhibited favorable energy for binding. The investigation of biological tests towards mosquito larvae indicates that Cr (III) and Mn (II) complexes manifest strong toxicity against Aedes aegypti larvae with 3.458 and 4.764 ppm values of lethal concentration LC50, respectively.